William Welch, head of Justice Department's anti-corruption unit, to leave post

William M. Welch II, the head of the Justice Department's public integrity unit, will step aside and return to Massachusetts, where he spent the bulk of his career exposing corruption in the state government, according to two sources familiar with the move.

Welch reached the decision after consulting with authorities about his family responsibilities and the professional opportunities in his home state, the sources added. He notified subordinates in the public integrity unit late Monday. He will remain an employee of the department's criminal division.

The unit, which leads some of the Justice Department's most explosive investigations of political figures, came under fire this year when Attorney General Eric H. Holder Jr. abandoned the case against former senator Ted Stevens (R-Alaska), who had been convicted on corruption charges, citing multiple lapses by the prosecution team in the sharing of evidence.

Six department lawyers -- including Welch, who supervised the case but did not play a major role during last year's trial -- remain the subject of a probe by the department's internal ethics investigators and a separate criminal investigation launched by U.S. District Judge Emmet G. Sullivan, who presided over the Stevens trial.

The sources said Welch's decision to leave Washington did not spring from an adverse finding by investigators. Welch's attorney, William Taylor of the Zuckerman Spaeder law firm in the District, said, "While the ultimate result in the Stevens case has been highly disappointing professionally and personally, Bill knows that his management decisions, where permitted, comported with his own and the department's highest ethical standards."

Welch's departure, set for Oct. 30, comes after the exit of several other lawyers connected to the Stevens case. Earlier this year, Brenda Morris, the section's deputy chief, relocated to Atlanta for personal reasons. Morris served as the government's lead voice during the Stevens trial and delivered a forceful cross examination of the senator. Two other section lawyers who worked on the Alaska case, Nicholas Marsh and Edward Sullivan, were transferred to the department's international affairs unit in June.

A Justice Department official, who spoke on the condition of anonymity to discuss personnel matters, said Raymond N. Hulser will serve as the unit's acting chief while department leaders conduct a nationwide search to fill the post, which those leaders described as vital. The unit's prosecutors are leading sensitive investigations of earmarks on Capitol Hill, among other cases.

Welch has headed the unit since March 2007. During his tenure, the office has continued to investigate figures tied to disgraced lobbyist Jack Abramoff, and it presided over the guilty plea of Samuel Kent, a former U.S. district judge in South Texas who was accused of assaulting female courthouse employees.

Lanny A. Breuer, assistant attorney general for the criminal division, said Wednesday that Welch is "a dedicated public servant who's devoted his entire professional life to serving the American people." He added that he and Welch had come to a "mutual decision" about what was best for the prosecutor and the division.